Recently, modern business telephone systems utilize microprocessor based telephone terminals on every user's desk. These audio terminals are usually digitally based, include various functions such as call blocking, call forwarding, etc., and are highly programmable. Indeed, a typical business telephone system includes dozens if not hundreds of microprocessors, since each audio terminal is, for all intents and purposes, a computer.
Despite the tremendous advance in computer and telephone technology, the basic function of taking a telephone off hook, waiting for dial tone, dialing a desired number, and establishing a communications channel with a remote user, has remained substantially unchanged for over a hundred years. Specifically, this protocol typically involves a user making a service request by taking a telephone off hook. The act of taking the telephone off hook causes a change in electrical state which is interpreted by the telephone switching equipment as a request by the user of that telephone for some type of service. The telephone switch, CO, PBX, or other similar equipment, then signals the user with an acknowledgement of the user's request for service. This acknowledgement is what is commonly termed as dial tone. The user then inputs the number corresponding to the desired remote user with which a connection is desired, and the switching equipment establishes the connection.
In modern telephone systems, a business entity usually has on-site telephone equipment which is termed, for example, a PBX. The PBX can establish connections between the public telephone network and any one or more users within the company, as well as between users within the company. Additionally, the PBX may be connected to computer equipment via a local area network such that communications can be established from a computer to the PBX, and out over the public telephone network. Additionally, a computer can be used to send a signal to the PBX, instructing the PBX to dial a remote user, and then ring back a local user within the company to thereby establish the connection.
For example, with reference to FIG. 1, the previously mentioned protocol might operate, in an exemplary embodiment, as follows: A user of computer 105a decides to call a remote user, either within the company or outside the company. The user of computer 105a then elects to do so by "clicking" on the particular user. This clicking is accomplished in a well known manner by placing a cursor within an icon and then activating a button.
The software in computer 105a transmits a signal over LAN 104 to PBX 101, which signal includes the desired remote number, as well as the requesting user's telephone number. The PBX receives the signal, dials the remote user, and then dials the telephone number of the requesting user. The communication channel is then established upon the requesting user and the called user picking up their handsets, thereby taking their respective telephones off hook. In systems where the requesting user's telephone is digital, the PBX can, if desired, automatically take the requesting user's telephone off hook so that after selecting the desired telephone number to be called, the user simply hears the remote telephone ringing as usual.
Several problems exist with the above arrangement. First, the user friendliness of the protocol leaves much to be desired. After the requesting user selects the number to be called, there is really little or no reason for him to have to have his phone ring and pick it up. If he is using an old fashioned standard analog telephone device, there is no way for the PBX to signal the device to automatically go off hook. Thus the user's phone must ring and he must physically take it off hook. Moreover, if the system is such that the requesting user has the more modern digital telephone equipment, then the fact that each telephone in the system is, in actuality, a microprocessor based audio terminal, greatly increases the cost of the system. Indeed, many systems presently manufactured require each user to have a telephone which costs many hundreds of dollars.
In view of the above, it can be appreciated that there exists a need of the prior art for a telephone system and switching arrangement whereby users can select a telephone number to be called from their computer and establish an audio connection with a remote user using a simple audio device rather than a complex digital device.